Optimise OS age detection

[CarterLi]

This is both simpler and faster, and it even support Windows.

{
    "type": "disk",
    "folders": "/",
    "key": "OS Age",
    "format": "{days} days"
}

HyDE/Configs/.config/fastfetch/config.jsonc

Line 109 in 4b6bd6e

"text": "birth_install=$(stat -c %W /); current=$(date +%s); time_progression=$((current - birth_install)); days_difference=$((time_progression / 86400)); echo $days_difference days"

[kRHYME7]

Thanks! @CarterLi 🫶